LOS ANGELES (Reuters) - More than 31 million Americans watched Michael Jacksons public memorial on television, but mystery surrounded the whereabouts of his body on Wednesday and plans for his burial. A day after Jacksons casket was taken to a Los Angeles basketball arena for an emotional memorial for fans, friends and his family, attention returned to how Jackson got his hands on powerful prescription drugs reportedly found in his rented mansion after his sudden death on June 25.